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Why is Your Heater Blowing Cold Air?

It’s that odd time of the year again in southeast Texas where we never know if it’s going to be cold or hot outside! With the frequent temperature changes, it’s hard to decide when we’re going to need to turn our heat on or AC. However, when a chilly day shows up and you really need some heat, the last thing you want to happen is for your heater to start blowing cold air instead of warm air. If this happens to you, and you’re wondering what’s going wrong, here are a few potential problems that could be the culprit! 

Your Furnace Hasn’t Warmed Up Yet

If this is your first time turning your heater on in a while, wait a few minutes to make sure your furnace isn’t just being a little slow. Allow your furnace to heat up for a little bit to get the heating cycle rolling.  After waiting about 10-15 minutes without any change in the air temperature, you can look at the rest of the items on this list to try to figure out what may be wrong with your heater.  

Your Thermostat Is on the Wrong Setting

Thermostats are such a helpful tool when it comes to the right temperature for your home, but it’s also easy for these little boxes to accidentally get set to the wrong settings sometimes. For example, your thermostat may still be set to its summer setting, which might be the reason it is still blowing cold air, even though the temperature is set on a warmer setting. Make sure that your thermostat is also set to “auto” instead of “on”, so that your furnace and fan will run at the same time like they are supposed to.  If all of the above checks out, your thermostat itself may be broken, which could be causing problems with communication to your furnace.  

The Filter Isn’t Clean

Since air filters catch all the dust floating through the air in our homes, they need to be changed regularly. If your furnace filter is too dirty, the airflow will be limited which can result in the heater overheating and turning off.  If this happens, cold air is going to be the only thing making it through.  Make sure that your air filter has been changed every 90 days, and if it’s been a while since your last air filter change, make sure to get it changed asap to help optimize your heater!

Your Furnace Has Overheated

If your furnace overheats, there is a safety feature that will automatically turn your furnace off in an attempt to stop any damage that could follow. If this happens, your heater will blow out cold air at first, and then eventually shut down, which could be a reason your furnace is blowing out cold air. There are a few reasons that your furnace could be overheating, aside from having a dirty furnace filter.

  • Dirt Buildup: If your filter happened to be dirty, then it is likely that there is dirt in other parts of your furnace as well, which can cause your furnace to overheat too.
  • Mechanical Failure: As you use your furnace, it is possible that one or two parts might stop working correctly. If this happens if might cause your furnace to overheat and shut down.
  • Age: Finally, as a furnace gets older, it will naturally stop working as well as it did when it was new. If too many parts start aging badly, that could be a potential cause of an overheated furnace. 

The Condensate Line Isn’t Working Correctly

Efficient furnaces will have condensate lines that take water and move it away from the furnace itself.  This is a helpful feature, but if there happens to be a clot in this condensate line, it will stop the furnace from actually igniting. This would mean that only cold air can come through the vents. There could be some other problems with your condensate line, but one of our HVAC specialists will be able to let you know for sure.  

There’s A Problem with the Gas

If the pilot light is not working correctly, there is a possibility that there could be an issue with the gas supply itself. It might be the case that there is not enough gas left in your tank, but it could also be an issue with how the gas is actually getting to your heater. These issues are best fixed by professionals, so schedule an appointment today so that we can take a look!

The Air Ducts Have a Leak 

If your air ducts have leaks, it can cause the hot air to leave before completely going through the vents.  This can happen because of age or even small animals biting at the ducts. This is a simple fix through! Typically resealing the ducts is all that is needed. We have well qualified HVAC specialists ready to inspect your air ducks to quicky find, and fix, the problem area.

For more HVAC tips, give our experts a call! If you’d like to make an appointment, contact us at 866-797-1535, or schedule an appointment online. Visit our website for more information on our vast number of services, including air conditioning, heating, duct cleaning, indoor air quality, maintenance, commercial HVAC, industrial, and marine services.

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